Add rate limiting to SMS

This commit is contained in:
dave 2017-11-20 19:31:59 -08:00
parent 9ed3d3d465
commit f000194af4
3 changed files with 65 additions and 0 deletions

View File

@ -4,6 +4,7 @@
This module provides ".text-<name> <message>" commands that send SMS messages
via the Twilio api.
Config
------
@ -19,6 +20,11 @@ Config
"guy1": "+11111111111",
"guy2": "+12222222222"
},
"limit": {
"enable": true,
"period": 900,
"max": 5
}
}
.. cmdoption:: account_sid
@ -45,6 +51,19 @@ Config
Dict of names to phone numbers. Names must be a-zA-Z0-9 and numbers match the format shown above.
.. cmdoption:: limit.enable
Enable or disable rate limiting. Rate limiting is controlled as a "burst bucket." If enabled, sending an SMS
requires 1 and removes one point from the bucket.
.. cmdoption:: limit.period
Every `limit.period`, a virtual point is added to the bucket.
.. cmdoption:: limit.max
When adding a point the bucket, the point will be discarded if the bucket already has `limit.max` points.
Twilio Setup
------------
@ -56,6 +75,7 @@ URL.
The webhook listener listens on `/app/gotsms`, so an example webhook URL would
be `http://1.2.3.4:3000/app/gotsms`.
Class Reference
---------------

View File

@ -7,5 +7,10 @@
"contacts": {
"guy1": "+11111111111",
"guy2": "+12222222222"
},
"limit": {
"enable": true,
"period": 900,
"max": 5
}
}

View File

@ -5,6 +5,8 @@
:synopsis: SMS client script (requires Twilio account)
"""
from time import time
from math import floor
from pyircbot.modulebase import ModuleBase, regex
import cherrypy
from threading import Thread
@ -62,6 +64,39 @@ class SMS(ModuleBase):
self.apithread = None
self.twilio = Client(self.config["account_sid"], self.config["auth_token"])
# limit-related vars
# How many messages can be bursted
self.bucket_max = int(self.config["limit"]["max"])
# burst bucket, initial value is 1 or half the max, whichever is more
self.bucket = max(1, self.bucket_max / 2)
# how often the bucket has 1 item added
self.bucket_period = int(self.config["limit"]["period"])
# last time the burst bucket was filled
self.bucket_lastfill = int(time())
def check_rate_limit(self):
"""
Rate limiting via a 'burst bucket'. This method is called before sending and returns true or false depending on
if the action is allowed.
"""
# First, update the bucket
# Check if $period time has passed since the bucket was filled
since_fill = int(time()) - self.bucket_lastfill
if since_fill > self.bucket_period:
# How many complete points are credited
fills = floor(since_fill / self.bucket_period)
self.bucket += fills
if self.bucket > self.bucket_max:
self.bucket = self.bucket_max
# Advance the lastfill time appropriately
self.bucket_lastfill += self.bucket_period * fills
if self.bucket >= 1:
self.bucket -= 1
return True
return False
def api(self):
"""
Run the webhook listener and block
@ -113,6 +148,11 @@ class SMS(ModuleBase):
if contact not in self.config["contacts"].keys():
return # TODO invalid contact
if self.config["limit"]["enable"]:
if not self.check_rate_limit():
self.bot.act_PRIVMSG(msg.args[0], "Sorry, try again later")
return
try:
self.twilio.api.account.messages.create(to=self.config["contacts"][contact],
from_=self.config["number"],